This invention relates to crack detection in internal combustion engine heads and in particular, to new and improved apparatus for locating cracks which cause leaks in the coolant passages of the engine head, and for closing off ports on the face of the head when locating the cracks.
In a typical system, the ports of the coolant passages are closed, air under pressure is introduced into the passages, and a leak detector fluid is applied to the head. Bubbles in the fluid indicate leaks and identify crack locations for repair. In such testing, it is desirable to use pressures in the order of 50 psi.
In one prior apparatus the head is mounted in a frame by transverse yokes. The frame is pivotally mounted in spaced uprights which permit the frame and head to be rotated for visual access to all sides of the head. Each coolant port on the face of the head is closed by a separate pad carried on an arm mounted on the frame. With this arrangement, the transverse support yokes and arms and the individual pads must be separately attached and adjusted. This is a time consuming job both in installation and removal. Also, since a large number of individual screws must be tightened, there usually is an additional problem with leakage around one or more ports when operating in the 50 psi range, calling for a first testing for port sealing and a second testing for cracks. In a variation, a face plate bolted onto the head is used in place of the individual pads and clamps for closing the face ports.
The present invention is designed to expedite the mounting of the face plate on the face of the head, and of the head, with the face plate, on the tester with a minimum of time in the plate mounting process.